For decades, mine operators in Northern Canada have stored waste rock and tailings waste—the "pulverized rock slurry" byproduct of mineral processing that's filled with skeevy chemicals like arsenic, lead, and mercury—in frozen dams reinforced with permafrost, an option far cheaper than constructing artificial structures to house the goop. But if such walls thaw, allowing air and water to interact with the highly reactive tailings, widespread "acid mine drainage" (AMD) could occur. Such a process can generate sulphuric acid and result in the leaching of heavy metals into nearby soil and water sources.

"Permafrost degradation is going to affect everything," says Magdalena Muir, research associate at the University of Calgary's Arctic Institute of North America. "When you have frozen infrastructure, you don't have to build an artificial structure and probably get used to not having to worry too much about breaches. But as soon as you have soil that behaves just like any other soil, you have all the issues you'd have in southern Canada."

The Canadian mining sector produces around one million tons of waste rock and 950,000 tons of tailings per day. As a result, the prospect of widespread AMD could be disastrous for the Canadian North: such scenarios would obviously be nightmares to contain, with the remoteness and cold climate seriously impeding cleanup. Think the Deepwater Horizon of the Arctic, except not nearly as visible and minus the dead dolphins to draw attention to the disaster. And like methane bubbling out of the permafrost, the situation only gets worse as it unfolds.

"Once a chemical process is underway—let's say, the oxidization of mining waste and leaching of heavy metals and acid drainage—it's much, much harder to stop that chemical process than just preventing it from the outset," says Ugo Lapointe, Canadian coordinator for MiningWatch. "It has its own momentum once it starts. Also, the plume of contamination downstream or underground are much harder to clean up and control once it starts, it's very, very costly."

As with most environmental issues in Canada, Indigenous people would likely be the hardest hit by acid mine drainage. Many Inuit, Dene, and Métis people in northern Canada continue to rely on hunting, fishing, and trapping for some sustenance and could face serious health consequences if chemicals leaked into the landscape. There's a concern that caribou herds may munch on vegetation that grows on the top of tailings ponds, which could result in the bioaccumulation of heavy metals in the food chain if the same animals are consumed.

A National Round Table on the Environment and the Economy report concisely summarized the impacts of mining excrement as "environmentally and socially disastrous, causing irreversible degradation of sensitive habitat and human health impacts."

Orphan Mines, Zombie Mines, and Straight-Up Disasters

While tailings dam failures have declined from 44 in the 1970s to seven in the 1990s according to the Fraser Institute, there have been some incredibly catastrophic snafus in recent years.

In August 2014, a tailings pond at British Columbia's Mount Polley active gold and copper mine broke, spilling 10 billion liters of wastewater and 5 billion liters of tailings waste into adjacent lakes and rivers. This was due to a "faulty design that didn't account for the instability of the glacial till on which it was constructed" (there are fears that it's going to happen again soon). Yellowknife's Giant Mine, closed in 2004, houses 237,000 tons of frozen arsenic trioxide and stills causes massive problems, with toxic tailings dust just blowing away from time to time. An underground mine in Northern British Columbia is currently bleeding acidic sludge into the Tulsequah River. Quebec's Raglan nickel mine is facing melting "dry stacks" of tailings, something Lapointe attributes to botched climate change predictions by its operator. And those are just the situations we know about.

John Sandlos—associate professor of history at Memorial University of Newfoundland and co-coordinator of the Abandoned Mines in Northern Canada Project—says oftentimes, it's not the big mines that concern experts who study issues like AMD. Sites like Giant, or Faro Mine in the Yukon, or Colomac Mine in the Northwest Territories are unequivocally difficult to remediate and will require decades of pricey palliative care. But at least they're on the radar. Conversely, there's no complete inventory of smaller mines that were abandoned over the past century, meaning that no one really knows which ones could potentially leach gunky shit. That could become a serious problem when precipitation increases due to climate change and spikes the probability of air and water socializing with long-frozen tailings.

"There were dozens of smaller mines: little dug holes or exploration sites, places where bulk sampling was done or a couple of tons of ore was taken out of the ground," says Sandlos, who co-authored the recently released Mining and Communities in Northern Canada: History, Politics and Memory. "We don't have a good handle on those sites—what might be there, what kinds of impacts might be flowing out of the sites. Not to suggest that all of them are leaking toxins every which way. But we just do not have the knowledge base right now."

An estimated 10,000 abandoned and orphaned mines are littered across the country, many of which require perpetual care but don't necessarily receive it. In the Northwest Territories and Yukon, that issue is exacerbated by the fact that jurisdiction for monitoring and remediating abandoned mines is largely a territorial responsibility, something which Kevin O'Reilly—a former Yellowknife city councillor and Giant Mine coordinator at Alternatives North—says can be difficult to execute given the lack of population and tax dollars in such areas to dedicate to esoteric environmental projects. In 2002, the federal government estimated it would cost over $555 million [$350 million USD] to clean up abandoned mines in the North, listing ten sites in the Northwest Territories and another four in the Yukon as "high-priority" and in need of urgent attention. Yet a single abandoned uranium mine in northern Saskatchewan is now estimated to cost $268 million [$187 million USD] to rehabilitate. Lapointe suggests recent estimates on the cost to clean up existing abandoned sites is likely "very, very conservative."

And we haven't even seen serious permafrost thawing yet. A 2014 study by Natural Resources Canada argued there are "no widespread requirements to consider climate change in mine planning or in mine closure plans." This matters when combined with a recent report from the Conference Board of Canada, which concluded that "many of the tailings have gone unchecked and uncontained for many decades." Waste rock piles and dams may have been designed with permafrost cores. But there are some big question marks about whether the "zombie mines"—a phrase Sandlos uses to describes mines that are no longer active but still exhibit life-like characteristics—will stay frozen forever, especially given we have no idea how climate change will manifest in coming decades in the highly volatile environment of the North.

Raising the (Very Low) Bar for Environmental Protection

To be sure, practices around tailings storage have improved significantly in recent years. David Chambers—president of Montana's Center for Science in Public Participation and expert on environmental effects of mining projects—recalls when the operators of Alaska's massive Red Dog zinc mine accidentally thawed a permafrost barrier between the tailings pit and a nearby tributary after it first opened in the late 80s. But over the last decade, Chambers says such operators have taken a much more realistic approach regarding the potential for permafrost thawing: "Back then, people would assume their waste rock piles are going to refreeze and then they wouldn't have to worry about them anymore," he says. Now, there's at least an industry-wide consensus on the potential long-term dangers of the problem. But given the brevity of a mine's life—usually between ten and 20 years—the real challenge is making industry care about it enough to plan for the worst.

Many new technologies have emerged in recent years to keep tailings frozen, with plenty of advances including passive refrigeration systems like thermosyphons, which remove underground heat, as well as physical impediments like thick gravel covers and dry stacking, the latter of which reduces tailings to about 85 percent solid (compared to traditional slurries which are about 50 percent solid). Some sites are also removing permafrost prior to construction. Many such approaches are being deployed at new mines, with different mechanisms used depending on climate change projections, permafrost quality, and geological composition (for instance, Sandlos says waste rocks at the abandoned Pine Point Mine, located on the south shore of Great Slave Lake, contain a lot of sulphur and would pose a serious AMD problem if the limestone that makes up the area's bedrock didn't neutralize the acidic effect).

Stéphane Robert, regulatory affairs manager for Agnico Eagle—which owns the massive Meadowbank Gold Mine in Nunavut—says the company's environmental impact assessment now includes a climate change modeling system that anticipates a worst case scenario of a 6.5 C [43.7 F] increase in average air temperature over 100 years. As a result of such modeling, the company's next project—titled Meliadine and located north of Rankin Inlet—will use dry stacking, the safest bet of the lot. Other mines in the North such as Ekati and Diavik (both in the Northwest Territories) have also expressed a devotion to the noble cause of keeping toxic feculence frozen as the rest of the world burns by investing in such technologies.

Given that the Conference Board of Canada projects Northern mining to grow by 91 percent between 2011 and 2020, this is indisputably positive news. Yet some still aren't convinced. Sandlos says that many initiatives concerning the preparation of permafrost-encased sludge pools for climate change are voluntary rather than enforced by governments. In addition, critics suggest that financial securities—the money gathered from an operator to pay for maintenance and potential problems after closure—tend to be too low for long-term perpetual care of a standard mining site, let alone for a gloopy disaster of the tailings breach variety.

"We don't have a strong regulatory regime that says you have to remediate a mine to a certain standard and make it look like it did before," Sandlos says. "We rely a lot on voluntary initiatives, we rely on the financial security. In a lot of ways, the government could do a better job regulating these things and putting in rules that mining companies know they have to do."

Lapointe says Quebec upped its game on the financial securities in 2013, but most other jurisdictions are still behind the times (Ontario, for instance, allows companies to do "self-assurance," meaning a company with a solid credit rating is trusted to make funds available if rehabilitation is required, something which Lapointe suggests "is not a solid security").

Considering the lack of knowledge about the potential impacts of climate change on permafrost degradation, it's also difficult to tell if the securities collected will be enough to deal with the damages, or if Canadians will be stuck with the bill for generations to come. Lapointe adds the decimation of the country's environmental law framework incurred with the passing of 2012's Bill C-45—impacting the Environmental Assessment Act, the Fisheries Act, the Navigable Waters Act—will also have to be undone to make tailings management effective.

"You need that solid environmental assessment process ahead of those projects to really tackle those long-term issues in a transparent and hopefully rigorous technical manner, but also in full consultation with those that are living on those lands for generations to come," he says. "That includes the permafrost aspect of all the things but we need to have a broader view of what priorities the government should have, and that's restoring environmental laws."

The Future Defrosted

The tricky thing about addressing the issue of mining regulations and the potential thawing of noxious discharge is the highly technical nature of it. In the course of ten minutes, Sandlos refers to the policy regime surrounding mines as "obtuse," "complicated," and a "web," involving dozens of entities and projects like the Federal Contaminated Sites Action Plan, Indigenous and Northern Affairs Canada, the Northern Contaminants Program, and Environment Canada.

As a result, the issues hasn't attracted as much attention from activists compared to, say, blockading the Keystone XL pipeline: "I don't know that concern is foremost on people's minds," Sandlos admits. It's doubtful that premiers and ministers, let alone the prime minister, will rank the issue of Frozen Mine Tailings That Might Leak Sometime In The Far-Off Future high on their sticky notes of shit to do.

And while mining operators are integrating climate predictions into construction—recall Agnico Eagle's worst-case scenario of a 6.5 C [43.7 F] rise over 100 years—recent studies suggest Arctic temperatures could spike to levels far worse than anticipated. A 2013 report estimated an end-of-century late fall temperature increase of 13 C [55 F] if business-as-usual policies are maintained, while the Northwest Territories government is anticipating a wintertime spike of 7.5 C [45.5 F] within 100 years. Natural Resources Canada has warned of 9 C [48 F] of warming by 2100 in the High Arctic.

The potential impacts of such a spike on the containment of tailings waste—not even to speak of the collapse of ice roads, buildings, and other pieces of critical infrastructure—could be unimaginably devastating. Yet in a 2009 survey, only 24 percent of mining practitioners identified mine drainage as the aspect of the company's operations most likely to be impacted by climate change, well behind impacts on processing (43 percent) and on-site transportation (41 percent). Until regulations or other mandatory measures are implemented, there's little reason to assume that would change.

Meanwhile, growth of the mining industry certainly won't be slowing down. Lapointe says the trend is that mining is moving north. The Conference Board of Canada has dubbed the sector the "future economic driver of Canada's North," with gold mines like Meadowbank opening across the region as the commodity's price skyrocketed in recent years. The country's also the silver medalist for nickel production in the world, and the fourth-largest producer of diamonds; in 2013, mining accounted for 3.4 percent of the country's GDP.

But in the same Conference Board report, tailings management and AMD issues was called "one of the greatest environmental challenges facing the mining industry today." And resolving the issue also costs a lot of money: when Agnico Eagle dumped tailings in a nearby fish habitat it put aside $48 million [$33 million USD] to seal it with a four-meter gravel cover. Most mining companies are publicly traded and operate with an explicit mandate to boost shareholder value, so such moves will likely be avoided unless required by law or consumer pressure.

The open letter signed by dozens of organizations and sent to every provincial and territorial energy and mines minister in July about the Mount Polley disaster implored recipients to "take immediate measures to assess the safety of existing and proposed tailings sites" and "maintain an inventory of sites and review results accessible to public." The newly elected federal Liberal government has already shown enthusiasm for facilitating inter-provincial cooperation on the climate change front, and could ostensibly extend such an attitude to the issue of dealing with tailings waste. But that's also assuming that such an issue is a) a priority for governments and b) one that can actually be successfully dealt with.

"If a mine requires long-term water treatment or keeping stuff frozen forever, maybe you shouldn't do it in the first place," O'Reilly concludes. "As human beings on this planet, we're not very good at managing things, even over a few decades, let alone thousands of years."